Mouthpiece cover



FIG. 1 is a top, front and right side perspective view of a mouthpiece cover showing my new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a left side view thereof.

The details shown in broken lines in FIGS. 1, 3, 5 and 6 are shown for illustrative purposes only and form no part of the claimed design. 

I claim the ornamental design for a mouthpiece cover, as shown and described. 